The prior art is documented with examples of vehicle head restraints with some form of latch or trigger release which permits the headrest to pivot relative to an uppermost location of a supporting seatback. A first example of this is the vehicle head restrain with electromagnetic locking and latch release mechanism of Fredriksson, US 2014/0265507. The electromagnetic mechanism is selectively moveable between a locked and an unlocked position, thereby allowing the head restraint to move between an upright and a folded position. The locked position includes engagement of a first lock member with a second lock member to prevent rotation of the head restraint relative to a base portion of the head restraint and the unlocked position includes disengagement of the first lock member from the second lock member to allow rotation of the head restraint relative to the base portion. An electromagnet is operatively connected to the head restraint and positioned to exert a magnetic force on the second lock member that urges the second lock member toward the unlocked position when the electromagnet is in an energized condition.
U.S. Pat. No. 8,197,001, to Grable, teaches a pivoting headrest assembly incorporated into a rear row vehicle seat including a base and a pivotally supported seatback. A first bracket is fixedly supported atop the seatback and exhibits a striker. A second bracket is pivotally supported to the first bracket in a biased direction away from the striker and includes a headrest bun support. A hook is supported upon the second bracket in a first biased direction engaging the striker. A release element associated with the second bracket is biased direction and which, upon being actuated in a second counter-biased direction, engages a projecting portion associated with the hook. A cable is secured at a first end to a fixed location associated with the seat and extends through a redirection location an offset distance from a pivot location of the seatback, the cable securing at a second end to the release element.
Sutter, Jr., U.S. Pat. No. 7,717,516, teaches an articulating/folding head restraint head restraint assembly that includes modular brackets that function as modules and allow for platform-ability and customization by varying auxiliary components. The modular brackets can be molded or cast using conventional manufacturing processes, and are designed to receive and/or house various components of the assembly such as pivotal head restraint supports, pivotal shafts, locking assemblies, etc. The modular brackets are designed to integrate a number of components that are typically separate in prior art devices and have to be individually assembled together.
U.S. Pat. No. 8,146,998, to Jammalamadaka, teaches a vehicle head restraint including a head restrain frame having at least one post for attaching the head restraint to a seat back. The head restraint is pivotable relative to the post and also includes a spring clip attached to the head restraint frame and a strop rigidly held relative to the post, such that the stop contacts the spring clip when the head restraint is in the upright position.
Sayama, US 2010/0078972, teaches a headrest that can be tilted from a head support state to a storage state by an operation at a position separate from the headrest, and an associated vehicle seat. The headrest includes a pillar mounted on the upper part of the seat back; a headrest frame turn-ably engaged with the pillar; a spring that urges the headrest frame to one side; a locking element or elements that hinder turning the headrest frame with respect to the pillar; a remote control section provided at a position separate from the headrest; and an inner cable one end part of which is connected to the locking element and the other end part of which is attached to the remote control section. The locking element or elements release by pulling the inner cable by the operation of the remote control section.
Finally, Yoshida U.S. Pat. No. 8,083,291 teaches a vehicle seat having a seat back, a seat bottom, and a headrest mounted on an upper portion of the seat back. The headrest includes a reverse U-shaped support section having downwardly extending two pillars and a horizontal section which connects upper portions of the pillars with each other. A lock plate is fixed to the horizontal section. A headrest frame is provided with an engagement disk which is changed over between a lock position where the engagement disk engages with the lock plate to disable the headrest to rotate about the horizontal section, and an unlock position where the engagement disk disengages from the lock plate to enable the headrest to rotate around the horizontal section.